The present invention relates to multi-coupling devices and primarily to a multi-coupling device for making connections between hydraulic lines running between disconnectable sections of a crane.
Construction equipment, such as cranes or excavators, often must be moved from one job site to another. Moving a crane or excavator can be a formidable task when the machine is large and heavy. For example, highway limits on vehicle-axle loads must be observed and overhead obstacles can dictate long, inconvenient routings to a job site.
One solution to improving the mobility of large construction machines is to disassemble them into smaller, more easily handled components. This typically involves undecking (separating) the upper works assembly from the lower works assembly. For larger cranes, further disassembly of the upper works and the lower works may be required. The individual components can then be transported separately to the job site where they are reassembled.
The typical past practice has been to undeck the upper works from the lower works. This disassembly of a conventional crane can also be both labor-intensive and time-consuming, adding additional expense to the undecking and redecking operations. This is primarily due to the large number of high-strength fasteners connecting the upper works assembly to the lower works assembly.
To overcome this problem, several quick disconnect systems have been developed. Several such machine designs, many of which are patented, are disclosed in an article entitled "Solving The Quick-Disconnect Problem For Big Bearings" in the Jul. 7, 1983 issue of Machine Design. For examples of previously patented approaches to solving this problem, see U.S. Pat. Nos. 4,478,340; 4,436,444; 4,248,488; 3,941,252; 3,923,407; 3,921,817; 3,726,418 and 2,965,245.
Finally, crane redecking can present alignment difficulties as well. In a conventional crane, the bearing bolt holes in the upper works assembly must be aligned precisely with the mounting-surface holes in the lower works assembly during redecking of the crane. Cranes employing quick disconnect systems which undeck at the swing bearing also require precise longitudinal, transverse and vertical alignment. Because the separate assemblies are large and heavy, such alignments can be unwieldy and time consuming. As a result, the separate assemblies are designed to align with a certain amount of tolerance from the desired position.
The upper works generally houses the prime power source, usually a source of pressurized hydraulic fluid such as a diesel engine powered hydraulic pump or pumps. The lower works usually include numerous hydraulicly powered components, such as hydraulic cylinders and motors for powering the crawlers, the swing drive, luffing jib winch, and auxiliary cylinders. The disconnection between the upper works and lower works thus also involves disconnecting the hydraulic lines between the pumps and the hydraulicly powered components. Where numerous hydraulic lines are involved, especially when they are of a large size and built to withstand high pressure, the disconnection and reconnection of these hydraulic lines can be a formidable task, even when each of the lines is fitted with a coupling designed for easy connection and disconnection.
One possible solution to having multiple couplings is to gang the couplings together so that all connections can be made simultaneously. However, even such a ganged coupling can present an additional problem. The tolerances required for aligning the couplings will be fairly small when compared with the tolerances in the alignment of the upper works and lower works. Thus, even when the upper works and lower works are aligned and secured together, the ganged couplings, respective halves of which are mounted on the upper works and lower works, may not be aligned sufficiently to make the coupling connections. Because of the massive size of the upper works and lower works, getting them better aligned, or reducing their alignment tolerance, is nearly impossible.